diff --git a/guava21/pom.xml b/guava21/pom.xml
index d6e556e4a0..930def2a67 100644
--- a/guava21/pom.xml
+++ b/guava21/pom.xml
@@ -4,8 +4,7 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
-    <groupId>com.baeldung.guava</groupId>
-    <artifactId>tutorial</artifactId>
+    <artifactId>guava21</artifactId>
     <version>1.0-SNAPSHOT</version>
 
     <parent>
@@ -15,12 +14,17 @@
      </parent>
 
     <dependencies>
-        <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
             <version>21.0</version>
         </dependency>
+
+        <dependency>
+            <groupId>org.jooq</groupId>
+            <artifactId>jool</artifactId>
+            <version>0.9.12</version>
+        </dependency>
     </dependencies>
 
 
diff --git a/libraries/src/test/java/com/baeldung/zip/ZipCollectionTest.java b/guava21/src/test/java/com.baeldung.guava.zip/ZipCollectionTest.java
similarity index 94%
rename from libraries/src/test/java/com/baeldung/zip/ZipCollectionTest.java
rename to guava21/src/test/java/com.baeldung.guava.zip/ZipCollectionTest.java
index 6f6a7b765f..866e09c6a0 100644
--- a/libraries/src/test/java/com/baeldung/zip/ZipCollectionTest.java
+++ b/guava21/src/test/java/com.baeldung.guava.zip/ZipCollectionTest.java
@@ -1,4 +1,4 @@
-package com.baeldung.zip;
+package com.baeldung.guava.zip;
 
 import com.google.common.collect.Streams;
 import org.jooq.lambda.Seq;
@@ -15,9 +15,9 @@ import static org.junit.Assert.assertEquals;
 
 public class ZipCollectionTest {
 
-    List<String> names;
-    List<Integer> ages;
-    List<String> expectedOutput;
+    private List<String> names;
+    private List<Integer> ages;
+    private List<String> expectedOutput;
 
     @Before
     public void setUp() throws Exception {
diff --git a/guava21/src/test/java/AtomicLongMapIntegrationTest.java b/guava21/src/test/java/com/baeldung/guava/tutorial/AtomicLongMapIntegrationTest.java
similarity index 97%
rename from guava21/src/test/java/AtomicLongMapIntegrationTest.java
rename to guava21/src/test/java/com/baeldung/guava/tutorial/AtomicLongMapIntegrationTest.java
index 9024329a56..273683710c 100644
--- a/guava21/src/test/java/AtomicLongMapIntegrationTest.java
+++ b/guava21/src/test/java/com/baeldung/guava/tutorial/AtomicLongMapIntegrationTest.java
@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.util.concurrent.AtomicLongMap;
 import org.junit.Test;
 
diff --git a/guava21/src/test/java/ComparatorsUnitTest.java b/guava21/src/test/java/com/baeldung/guava/tutorial/ComparatorsUnitTest.java
similarity index 98%
rename from guava21/src/test/java/ComparatorsUnitTest.java
rename to guava21/src/test/java/com/baeldung/guava/tutorial/ComparatorsUnitTest.java
index 3d1f2e9e81..0183e6cf3a 100644
--- a/guava21/src/test/java/ComparatorsUnitTest.java
+++ b/guava21/src/test/java/com/baeldung/guava/tutorial/ComparatorsUnitTest.java
@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.Comparators;
 import org.junit.Assert;
 import org.junit.Test;
diff --git a/guava21/src/test/java/GuavaStreamsUnitTest.java b/guava21/src/test/java/com/baeldung/guava/tutorial/GuavaStreamsUnitTest.java
similarity index 99%
rename from guava21/src/test/java/GuavaStreamsUnitTest.java
rename to guava21/src/test/java/com/baeldung/guava/tutorial/GuavaStreamsUnitTest.java
index 96b4a2ffdb..56c172ca87 100644
--- a/guava21/src/test/java/GuavaStreamsUnitTest.java
+++ b/guava21/src/test/java/com/baeldung/guava/tutorial/GuavaStreamsUnitTest.java
@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.Streams;
 import org.junit.Assert;
 import org.junit.Before;
diff --git a/guava21/src/test/java/InternBuilderUnitTest.java b/guava21/src/test/java/com/baeldung/guava/tutorial/InternBuilderUnitTest.java
similarity index 91%
rename from guava21/src/test/java/InternBuilderUnitTest.java
rename to guava21/src/test/java/com/baeldung/guava/tutorial/InternBuilderUnitTest.java
index 183e3eeb43..13d8f5f3b7 100644
--- a/guava21/src/test/java/InternBuilderUnitTest.java
+++ b/guava21/src/test/java/com/baeldung/guava/tutorial/InternBuilderUnitTest.java
@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.Interner;
 import com.google.common.collect.Interners;
 import org.junit.Assert;
diff --git a/guava21/src/test/java/MonitorUnitTest.java b/guava21/src/test/java/com/baeldung/guava/tutorial/MonitorUnitTest.java
similarity index 97%
rename from guava21/src/test/java/MonitorUnitTest.java
rename to guava21/src/test/java/com/baeldung/guava/tutorial/MonitorUnitTest.java
index e29d4a1eeb..a3a9a4f838 100644
--- a/guava21/src/test/java/MonitorUnitTest.java
+++ b/guava21/src/test/java/com/baeldung/guava/tutorial/MonitorUnitTest.java
@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.util.concurrent.Monitor;
 import org.junit.Assert;
 import org.junit.Test;
diff --git a/guava21/src/test/java/MoreCollectorsUnitTest.java b/guava21/src/test/java/com/baeldung/guava/tutorial/MoreCollectorsUnitTest.java
similarity index 95%
rename from guava21/src/test/java/MoreCollectorsUnitTest.java
rename to guava21/src/test/java/com/baeldung/guava/tutorial/MoreCollectorsUnitTest.java
index 5950997788..acd03022d2 100644
--- a/guava21/src/test/java/MoreCollectorsUnitTest.java
+++ b/guava21/src/test/java/com/baeldung/guava/tutorial/MoreCollectorsUnitTest.java
@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.MoreCollectors;
 import org.junit.Assert;
 import org.junit.Test;
diff --git a/guava21/src/test/java/StreamUtility.java b/guava21/src/test/java/com/baeldung/guava/tutorial/StreamUtility.java
similarity index 97%
rename from guava21/src/test/java/StreamUtility.java
rename to guava21/src/test/java/com/baeldung/guava/tutorial/StreamUtility.java
index 1eb866fb88..b730fbf558 100644
--- a/guava21/src/test/java/StreamUtility.java
+++ b/guava21/src/test/java/com/baeldung/guava/tutorial/StreamUtility.java
@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import org.junit.Assert;
 
 import java.util.Iterator;
diff --git a/libraries/pom.xml b/libraries/pom.xml
index 0373d54429..a3b78f1695 100644
--- a/libraries/pom.xml
+++ b/libraries/pom.xml
@@ -349,12 +349,6 @@
             <artifactId>java-lsh</artifactId>
             <version>${java-lsh.version}</version>
         </dependency>
-        <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>21.0</version>
-        </dependency>
         <dependency>
             <groupId>au.com.dius</groupId>
             <artifactId>pact-jvm-consumer-junit_2.11</artifactId>
diff --git a/libraries/src/main/java/com/baeldung/zip/ZipCollectionExample.java b/libraries/src/main/java/com/baeldung/zip/ZipCollectionExample.java
deleted file mode 100644
index 3df9baad69..0000000000
--- a/libraries/src/main/java/com/baeldung/zip/ZipCollectionExample.java
+++ /dev/null
@@ -1,40 +0,0 @@
-package com.baeldung.zip;
-
-import com.google.common.collect.Streams;
-import org.jooq.lambda.Seq;
-
-import java.util.Arrays;
-import java.util.List;
-import java.util.stream.IntStream;
-
-public class ZipCollectionExample {
-    static List<String> names = Arrays.asList("John", "Jane", "Jack", "Dennis");
-
-    static List<Integer> ages = Arrays.asList(24, 25, 27);
-
-    public static void main(String[] args) {
-        //      Using Streams API from Guava 21
-        Streams
-          .zip(names.stream(), ages.stream(), (name, age) -> name + ":" + age)
-          .forEach(System.out::println);
-
-        //        Using native Java 8 Int Stream
-        IntStream
-          .range(0, Math.min(names.size(), ages.size()))
-          .mapToObj(i -> names.get(i) + ":" + ages.get(i))
-          .forEach(System.out::println);
-
-        //      Using jOOL
-        Seq
-          .of("John", "Jane", "Dennis")
-          .zip(Seq.of(24, 25, 27));
-
-        Seq
-          .of("John", "Jane", "Dennis")
-          .zip(Seq.of(24, 25, 27), (x, y) -> x + ":" + y);
-
-        Seq
-          .of("a", "b", "c")
-          .zipWithIndex();
-    }
-}
diff --git a/pom.xml b/pom.xml
index 818d131359..6c0b0911e0 100644
--- a/pom.xml
+++ b/pom.xml
@@ -57,6 +57,7 @@
         <module>guava</module>
         <module>guava18</module>
         <module>guava19</module>
+        <module>guava21</module>
         <module>guice</module>
         <module>disruptor</module>